There are 'n' number of names and terminologies in dermatology. The real and unreal names lead to lot of confusion to the residents and practitioners of dermatology. The word 'pseudo' means 'unreal', 'false' or 'fake', and it has deep roots in dermatology providing herculean task to differentiate and understand the real conditions/diseases/signs in dermatology. We have made an attempt to list and describe the pseudo and associated real conditions in dermatology.

Skin tumors are tumors arising from keratinocyte and from adnexal structures. Immunohistochemistry is very helpful in diagnosis of difficult cases in epithelial skin neoplasms, especially basal cell carcinoma (BCC) which is positive for BerEP4, a keratin marker, and mostly negative for epithelial membrane antigen (EMA). Squamous cell carcinoma cells are positive for EMA and cytokeratin, which are of higher molecular weight than those found in BCC. In contrast to BCC, trichoblastoma and trichoepithelioma are negative for androgen receptors. Of the malignant dermal spindle cell lesions, spindle cell squamous carcinoma is positive to 34 betaE12, desmoplasmic melanoma is positive to S100, and leiomyosarcoma is positive to desmin. Of the malignant pagetoid cells, Paget's disease is positive to CK7 and cam5.2, whereas the pagetoid variant of Bowen's disease is positive to CK 5/6. Melanoma in-situ is positive to both S100 and melan-A. Immunohistochemistry is an extremely valuable adjunct to standard morphologic diagnosis in diagnostic pathology. Diagnosis of epithelial tumor depends largely on morphological features but, in rare cases, immunohistochemical stains are needed for definitive diagnosis.

Direct immunofluorescence (DIF) and indirect immunofluorescence (IIF) tests on skin biopsy are being done mostly in academic teaching hospitals. These tests provide a useful diagnostic aid to dermatologists. Immunohistology and serology can, in conjunction with histology, provide considerable help in delineation and diagnosis of various skin disorders as well as systemic diseases with skin involvement, e.g. systemic lupus erythematosus. Immunofluorescence (IF) studies have now become an invaluable supplement to clinical and histological examination in a variety of dermatological diseases. These skin diseases now include not only bullous and connective tissue disorders, vasculitides, and conditions such as lichen planus, but also the scaling dermatoses, notably psoriasis. In this review article, we share our experience of providing such a diagnostic facility for more than 30 years in a large tertiary care health center in North India and also help to outline the conditions, which can be diagnosed confidently, and others where IF can help in confirming a diagnosis or the immune component of the disease. The article also deals with handling of skin biopsy specimens and interpretation of biopsy findings on DIF and IIF examination.

Background: Mechanism leading to an abrupt hair loss in diffuse alopecia areata (AA) remains unclear. Aims: To explore the characteristics of diffuse AA and possible factors involved in its pathogenesis. Methods: Clinical and laboratory data of 17 diffuse AA patients and 37 patchy AA patients were analyzed retrospectively. Serum IgE level was evaluated in all diffuse and patchy AA patients, as well as 27 healthy subjects without hair loss to serve as normal control. Univariate analysis was performed using Fisher's exact test and Wilcoxon rank-sum test. Associations between inflammatory cell infiltration and laboratory values were analyzed using Spearman rank correlation test. Results: The mean age of patients with diffuse AA was 27 years with a mean disease duration of 1.77 months. All of them presented in spring or summer with an acute onset of diffuse hair loss preceded by higher incidence of scalp pruritus. Although no statistically significant difference on the incidence of atopic disease among three groups has been found, serum IgE level in diffuse AA was higher than that in healthy controls, but was comparable to that in patchy AA group. Histopathology of lesional scalp biopsies showed more intense infiltration comprising of mononuclear cells, eosinophils, CD3 + , and CD8 + T cells around hair bulbs in diffuse AA group than in patchy AA group. Moreover, IgE level in diffuse AA patients positively correlated with intensity of infiltration by mononuclear cells, eosinophils, and CD8 + T cells. Conclusions: Hypersensitivity may be involved in pathogenesis of diffuse AA. The acute onset of diffuse AA may be related to intense local inflammatory infiltration of hair loss region and an increase in serum IgE level.

Background: Segmental vitiligo is a small but unique subset of vitiligo requiring due importance due to its lack of response to medical treatment but excellent response to surgical treatment. Characterization of the pattern of segmental vitiligo will also help to understand the pathogenesis of the disease. Aim: To characterize clinically the features of segmental vitiligo, a cross-sectional clinical study at dermatology outpatient department at AIIMS was carried out. Methods: Consecutive 188 patients were evaluated to characterize the clinical features of segmental vitiligo by detailed history, clinical examination, and photography. Frequency of each clinical feature was calculated. Results: Certain features such as early onset, initial progression of disease followed by stability, blaschkoid pattern, irregular margins, leucotrichia within and beyond the vitiligo lesion, and islands of pigmented macules within the vitiligo lesion were found to be characteristic of the disease. Conclusions: A combination of various features such as early onset of disease, blaschkoid pattern, irregular margins, leucotrichia, and islands of pigmented macules within the vitiligo lesion are helpful in diagnosis of the disease.

Epidermolysis bullosa (EB) is a group of inherited, mechanobullous disorders that are caused by mutations in the structural proteins in the epidermis or dermoepidermal junction. Characteristic clinical picture is the presence of blisters at trauma prone areas of the body, which develops at or soon after birth. Availability of specific monoclonal antibodies against the target proteins together with advances in the molecular genetics have led to the revision in the classification of EB. Now four major types of EB are recognized depending upon the level of blister and the location of target protein: EB simplex (epidermolytic), junctional EB (lucidolytic), dystrophic EB (dermolytic) and Kindler's syndrome (mixed cleavage plane). The laboratory tests not only help to confirm the diagnosis of EB but are also an important tool to classify (and subtype) EB. These include immunofluorescence antigen mapping (IFM), transmission electron microscopy (TEM) and mutation analysis. IFM is the most preferred method for final diagnosis of EB worldwide. It is relatively easy to perform and results can be obtained rapidly. This article describes the technicalities and significance of IFM in various types of EB.

Background: We are reporting 35 new cases of Chromoblastomycosis from Central Kerala. A majority of the cases from India are reported from the Sub Himalayan belt and South India. The disease scenario in India and abroad is briefly reviewed. Aims: To study chromoblastomycosis in Central Kerala including the demographic and clinico- investigative profile. Methods: This report is a retrospective record analysis of 35 cases of chromoblastomycosis who presented to the Dermatology Outpatient department of our tertiary center from January 2003 to July 2010 after obtaining Institutional Review Board approval. Results: The disease was found to be more common among male agriculturists. The majority of cases were from the central districts of Kerala in and around the Western Ghats. The lower extremity (60%) was more affected with 40% of the subjects remembering a prior history of trauma. Sclerotic bodies were demonstrable in scrapings from black dots in 42.8%. The characteristic mixed mycotic granuloma was demonstrable in 77.1% of cases. The most common species isolated was Fonsecaea pedrosoi. Conclusions: Chromoblastomycosis is very common in Central Kerala. The disease mainly affects male agriculturists especially those employed in rubber plantations. The most common organism is F. pedrosoi.

Background: The prevalence, clinical patterns, and causative drugs of cutaneous adverse drug reactions (cADR) vary among the different populations previously studied. Aim: To determine the prevalence, the clinical patterns of drug eruptions, and the common drugs implicated, particularly in severe cADR such as Stevens-Johnson Syndrome/Toxic epidermal necrolysis (SJS/TEN) and drug rash with eosinophilia and systemic symptoms (DRESS) in our population. Methods: We analyzed the database established for all cADR seen by the department of Dermatology from January 2001 till December 2010. Results: A total of 362 cADR were seen among 42 170 new clinic attendees, yielding an incidence rate of 0.86%. The most common reaction pattern seen was maculopapular eruption (153 cases) followed by SJS/TEN (110 cases) and DRESS (34 cases). Antibiotics was the most commonly implicated drug group (146 cases) followed by anticonvulsants (81 cases) and antigout drugs (50 cases). The most frequently implicated drug was allopurinol (50 cases). Carbamazepine, allopurinol, and cotrimoxazole were the three main causative drugs of SJS/TEN accounting for 21.8%, 20.9%, and 12.7%, respectively, of the 110 cases seen, whereas DRESS was mainly caused by allopurinol (15 cases). Mortality rates for TEN, SJS, and DRESS were 28.6%, 2.2%, and 5.9%, respectively Conclusions: The low rate of cADR with a high proportion of severe reactions observed in this study was probably due to referral bias. Otherwise, the reaction patterns and drugs causing cADR in our population were similar to those seen in other countries. Carbamazepine, allopurinol, and cotrimoxazole were the three main causative drugs of SJS/TEN in our population.

Background: Bullous pemphigoid (BP) is an acquired autoimmune subepidermal blistering disease characterized by circulating IgG autoantibodies directed against BP180 and BP230 hemidesmosomal proteins. Previous studies have demonstrated that antibodies against the NC16a domain of BP180 mediate BP pathogenesis, while antibodies against BP230 enhance the inflammatory response. Recently, commercial BP180-NC16a enzyme-linked immunosorbent assay (ELISA) and BP230 ELISA kits were developed to detect anti-BP180 and anti-BP230 autoantibodies in human BP sera. Aims: To evaluate the efficacy of BP180-NC16a ELISA and BP230 ELISA in the initial diagnosis of BP. Methods: Sera from 62 BP patients and 62 control subjects were tested by BP180-NC16a ELISA and BP230 ELISA and compared with findings from indirect immunofluorescence (IIF) and immunoblotting (IB) to determine the sensitivity and specificity of these assays. Results: The sensitivities of BP180-NC16a ELISA and BP230 ELISA were 87.1% (54/62) and 56.5% (35/62), respectively, and the specificities of both were 100% (62/62). Using both ELISAs for diagnosis increased the sensitivity to 95.2% (59/62) and was statistically comparable with IB sensitivity. Conclusions: ELISA is a convenient, effective, and reliable method for serodiagnosis of BP, and combined use of BP180-NC16a ELISA and BP230 ELISA can increase the sensitivity of this diagnostic approach.